Forbes columnist Steven Salzberg and author-investigator Joe Nickell will each be awarded the 2012 Robert P. Balles Prize in Critical Thinking, to be presented by the Committee for Skeptical Inquiry at the CFI Summit in October.

The Aura: A Brief Review

Empirical studies show no evidence for the existence of an aura around humans that supposedly only psychics can see. Why, then, does belief in auras persist?

“I used equipment
he invented as well as adaptations made of Dr. Walter J. Kilner's
screens for some years before I discovered that my eyes could see auras
without visual aids.” -J.C. Pierrakos (2005)

One might feel compelled to reread
the above quote because, after all, there is presently no objective
evidence for the existence of auras. The word aura itself comes from a Greek word meaning breeze.
The aura is claimed to be a glowing field surrounding a human being
that is undetectable, except by gifted psychics. By interpreting the
aura of an individual, one is said to be able to deduce personality,
health, and present emotions (Randi 1995).

Believers
in the aura describe it as a “vital force [that] spills beyond the
perimeters of the skin into the atmosphere to create an energy field,
or aura, which provides a

great deal
of information about the nature and functioning of human beings” (Pierrakos
2005, 18). Many methods have been used to test whether the aura exists.
One method has been to test gifted individuals who claim to see auras.
Attempts have also been made to look for auras with the aid of various
instruments and apparatus. The great majority of these tests, which
we review here, have shown limited or no evidence for the reality of
auras. In spite of the lack of empirical evidence, proponents continue
to advocate their existence. In the second part of this article we will
discuss several explanations for proponents' continued belief in spite
of the lack of evidence.

Empirical Studies of Auras

An obvious
method for testing the existence of auras is to test psychics who claim
to be able to detect them. In one such experiment, a windowless television
studio with a barrier in the center and entrances at each end was used
(Loftin 1990). A psychic and an experimenter stood on one side of the
barrier while one or two subjects entered the studio on the other side.
The psychic had less than three minutes to discern how many auras she
detected. Two white-noise generators were used to cover any subtle sound
cues, such as the sound of breathing, that might give away how many
subjects were present in the room. Not surprisingly, the psychic did
not score above chance.

Another
experiment had a more elegant methodology (Gissurarsson and Gunnarsson
1997). It took place in a room that contained four screens made from
unpainted fiberboards, which were placed in a row on one wall of the
room. In this experiment, unlike in the one previously described, a
control group was used. Ten aura seers and nine non-seers (the control
group) were selected to participate in the experiment. All of the participants
had to guess behind which one of the four screens the experimenter was
hidden. This task was based on the assumption that the aura radiates
a few inches from the body and should have been visible above the screen.
Blinds covered the large windows on the wall behind the screens, and
the whole
wall was covered with brown paper.
Suggestive shadows were eliminated through the use of Luxo lamps positioned
across from the screens. A total of thirty-six sessions consisting of
1,449 trials was run. The results were non-significant for both groups,
although “the control group did slightly better than the experimental
group” (Gissurarsson and Gunnarsson 1997, 41).

Attempts
have been made to measure the aura objectively and experimentally. Various
instruments have been used or even invented for the purpose of observing
the aura. In the early 1900s, W.J. Kilner thought that the aura could
be made visible through the use of dicyanin screens containing a coal-tar
dye. The dye appeared to alter the sensitivity of the eye by “making
the observer temporarily short-sighted and therefore more readily able
to perceive radiation in the ultra-violet band” (Kilner 1965, viii).
Kilner studied the human aura for diagnostic purposes and made an explicit
disclaimer of any clairvoyant or occult preoccupation. Ironically, the
spiritualist movement quickly endorsed Kilner's findings as proof
of existence of the aura. Shortly thereafter, aura spectacles and aura
goggles were invented, based on the idea of the dicyanin screens (Gissurarsson
and Gunnarsson 1997).

Existing
instruments have also been used to attempt to quantitatively measure
the radiation that an aura supposedly emits. A photomultiplier tube,
a highly sensitive device, has been used to try to detect this radiation
(Dobrin et al. 1977). The photomultiplier responds to small quantities
of light by producing measurable amounts of electric charge. The amount
of charge produced is proportional to the amount of light detected by
the tube. This tube responds to light in the visible and ultraviolet
range but not in the infrared range, which rules out heat effects. This
experiment demonstrated that humans do reflect energy in the visible
and ultraviolet spectrum, but this is not surprising. If the human body
did not reflect energy in the visible range,
it would be invisible.

Kirlian
photography has also been used in the attempted examination of auras.
A Kirlian photographic image of an object is obtained when a large electric
potential is applied between the object and a dielectrically isolated
electrode (Pehek et al. 1976). A famous instance in which Kirlian photography
seemed to prove the reality of the aura happened when a section of a
plant leaf was photographed and then torn away. The leaf was then rephotographed,
which resulted in a faint image of the torn-out section still appearing
in the second photo (Randi 1995). The luminous low-current gaseous discharge,
known as a corona
discharge-resulting
from variance in pressure, humidity, grounding, and conductivity surrounding
the leaf-persisted temporarily after the torn part was removed and
was responsible for the Kirlian image of a complete leaf (Pehek et al.
1976).

Continued Belief in Auras

Seeing auras
is actually one of the less common psychic experiences. Zingrone,
Alvarado, and Agee concluded, based on a review of studies of the general
population, that the “prevalence [of seeing auras] ranged from 0%
to 6%” (2009, 161).

One
explanation for the persistence of belief in auras, given that there
is essentially no objective evidence for their reality, could be rare
cases of synesthesia. Synesthesia is a nonpathological neurological
condition in which sensory experiences that are usually separate are
experienced together. The most common type is color–number/letter
synesthesia, in which the synesthete perceives numbers and letters
in color (Spector and Maurer 2009). In a rarer type, colors are associated
with faces. Ward (2004) reported a case study of G.W., a synesthete
who experienced a color for names of people whom she knew personally.
She reported that she perceived colors occupying her whole field of
vision when her synesthesia was elicited by words. G.W. distinctly visually
perceived the names and faces of people she knew with colored halos
or “auras” projected around the person or name. “G.W. does not
believe that she has mystical powers and has no interest in the occult.
However, it is not hard to imagine how, in a different age, such an
interpretation could arise” (Ward 2004, 770). There are other case
studies in which synesthetes report projecting colors onto people (Riggs
and Karwoski 1934; Collin 1929; Cytowic 1989; Weiss et al. 2001; Ramachandran
and Hubbard 2001 as cited in Ward 2004). It is especially interesting
that in two separate samples, Zingrone, Alvarado, and Agee (2009) found
that individuals who reported seeing auras were significantly more likely
to report synesthetic events.

There
are other explanations why belief in the existence of auras might persist.
Perceptual distortions, illusions, and hallucinations might promote
belief in auras. Physiological processes, such as rare cases of human
luminescence caused by bacterial infections, might also be responsible
for some reports of auras (Alvarado 1987). Psychological factors,
including absorption, fantasy proneness, vividness of visual imagery,
and after-images, might also be responsible for the phenomena of the
aura. Gissurarsson and Gunnarsson (1997) discuss four classes, or
models, of possible explanations: scientific, clinical, psychical, and aura
imagery. In the scientific model, for example, an individual might
experience visions of a series of colored halos surrounding another
person's head. This phenomenon is known as “the glory” and usually
occurs outdoors under certain meteorological conditions when a shadow
is projected on a cloud of uniform water droplets. In the clinical model,
seeing an aura might be related to epilepsy. Although epileptic auras
are usually olfactory or emotional, visual auras also have been reported.
Migraine headaches commonly result in visual phenomena that could
easily be interpreted as auras (Sacks 1985). Eye disorders might also
account for aura-like experiences. According to the psychical
model, auras might be
attributed to unknown electromagnetic field radiation energy that somehow
is visible to only some individuals. This seems highly unlikely. The aura imagery model suggests that individuals who claim to see auras might actually be perceiving a person through their senses while their mind and memory reinterpret this information as the experience
of luminous beings.

Psychological
factors positively related to claims of psychic experiences might
also contribute to the belief in the phenomenon of the aura (Zingrone
et al. 2009). One study (Alvarado and Zingrone 1994) reported
that aura vision was related to higher levels of reports of vividness
of visual imagery and of imaginative-fantasy experiences. In another
study, a positive relationship between auras and the claims of other
psychic experiences was found (Zingrone et al. 2009).
Seeing auras has been associated more with aspects of absorption and
less with aspects of dissociative processes. Absorption was described as “a predisposition
towards the processing of unusual perceptual input or of imagery”
(Zingrone et al. 2009, 163). These authors also found that people
reporting seeing auras were also more likely to report precognitive
dreams, lucid and more vivid dreams, and out-of-body experiences.

Psychological factors, such as fantasy proneness, suggestibility, and
the like, are related to levels of dopamine activity in the brain (see
Raz et al. 2008 for a brief review). Catechol-O-methyltransferase (COMT)
is an enzyme that breaks down dopamine in the brain. It has been found
that which allele of the COMT gene an individual has is related to the
degree of his or her suggestibility and hypnotizability (Raz 2007).
Thus, propensity to see auras may have, at least in part, both a neurochemical
and a genetic basis.

In
summary, although there is ample evidence that human beings are surrounded
by thermal, electromagnetic, and electrostatic fields (Presman 1970
as cited in Dobrin et al. 1977), there is a lack of evidence for the
existence of the aura that psychics claim to see. Continued
belief in the reality of auras can be attributed to several psychological,
neurological, and optical effects.

References

Alvarado,
C.S. 1987. Observations of luminous phenomena around the human body:
A review. Journal
of the Society for Psychical Research
54: 38–60.

Bridgette M. Perez and Terence Hines are in the Psychology Department at Pace University in Pleasantville, New York. Hines is a Committee for Skeptical Inquiry scientific consultant and author of Pseudoscience and the Paranormal (Prometheus Books 2003). Email: TerenceHines@aol.com.

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